Processes for forming a fiber-reinforced product

ABSTRACT

A process for forming a reinforced product suitable for use as a roofing material is provided, comprising: (a) providing a composition comprising a matrix material; and (b) extruding the composition with an extruder to form a reinforced product, wherein a plurality of fibers is combined with the matrix material prior to or during the extrusion step. Also provided is a process for forming a reinforced product suitable for use as a roofing material, comprising: (a) forming a first layer comprising a first matrix material; (b) providing a plurality of fibers on the first layer; (c) forming a second layer comprising a second matrix material, above the plurality of fibers; and (d) combining the plurality of fibers with the first matrix material and/or the second matrix material, to form a reinforced product.

BACKGROUND

Structurally reinforced products can be used in a variety ofapplications including, for example, roofing applications in residentialand commercial buildings. Conventional processes for forming suchreinforced roofing materials are somewhat inflexible. Typically, variousparameters of such conventional processes are restricted, and varyingsuch process conditions can be problematic or even impossible. Forexample, conventional processes typically do not provide ampleflexibility in varying the overall compositions of the polymericmaterials so reinforced, as well as reinforced products formedtherefrom. In addition, conventional processes typically requirerelatively large quantities of material for processing in order to beeconomically feasible, and this can in turn require the use of largepieces of process equipment and excessive energy to accommodate theprocessing of such materials. Furthermore, conventional processestypically require the combination of a matrix and a fiber structurewherein a matrix is formed by one process, and reinforcing material ispreformed by a separate process into a preliminary structure. The Use ofsuch conventional processes generally leads to decreased efficiency andincreased manufacture cost.

SUMMARY

According to one aspect, a process for forming a reinforced productsuitable for use as a roofing material is provided, comprising:

(a) providing a composition comprising a matrix material; and (b)extruding the composition with an extruder to form a reinforced product,wherein a plurality of fibers is combined with the matrix material priorto or during the extrusion step.

According to another aspect, a process for forming a reinforced productsuitable for use as a roofing material is provided, comprising:

(a) forming a first layer comprising a first matrix material;

(b) providing a plurality of fibers on the first layer;

(c) forming a second layer comprising a second matrix material, abovethe plurality of fibers; and

(d) combining the plurality of fibers with the first matrix materialand/or the second matrix material, to form a reinforced product.

According to another aspect, a process for forming a plurality ofprecursor particles suitable for use in a process for forming areinforced product is provided, comprising:

(a) providing at least one continuous fiber;

(b) at least partially coating the at least one continuous fiber with amatrix material; and

(c) dividing the at least partially coated continuous fiber to form aplurality of precursor particles.

According to another aspect, a process for forming a reinforced productfrom a plurality of precursor particles is provided, wherein eachprecursor particle comprises a fiber at least partially coated with amatrix material, the process comprising:

(a) heating the plurality of precursor particles under conditionseffective to at least partially melt the matrix material, therebyproducing a heated material; and

(b) introducing the heated material to a surface on which the reinforcedproduct is formed.

DETAILED DESCRIPTION

The process for forming the reinforced product employs a matrix materialthat can be selected based on the intended application of the reinforcedproduct, the specific fabrication process that is employed, and/or thedesired characteristics and properties of the product. For example, thematrix material can include a polymeric material such as a thermoplasticor a thermosetting material. The matrix material can be formed frombitumen, polymer-modified bitumen, resins, rubbers and plastics such aspolyvinyl chloride (PVC), thermoplastic olefin (TPO), polyethylene,polypropylene, ethylene propylene diene monomer (EPDM) and polymersthereof, polyester, polyurethane, polyisocyanurate,propylene-ethylene-copolymer and a mixture thereof. Examples of apropylene-ethylene-copolymer which can be used are available fromMontell Polyolefins under the trade names “ASTRYN” and “ADFLEX”. Forroofing applications, the matrix material preferably can at leastinclude bitumen or a polymer-modified bitumen.

The polymer-modified bitumen contains at least one polymer for impartingdesirable characteristics to the reinforced product. For example, apolymer additive can be used to improve various characteristics of thereinforced product such as, for example, the thermal response,structural flexibility, aging characteristics, and/or adhesioncharacteristics of the reinforced product. The polymer used to modifythe bitumen can include, for example, styrene butadiene styrene rubber,amorphous-poly-alpha olefins (APAOs), isotactic polypropylene or amixture thereof. The polymer additive used to modify the bitumen can bepresent in any effective amount.

The amount of the matrix material can depend on, for example, theintended application of the product, the specific fabrication processemployed, and/or the desired characteristics and properties of theproduct. The matrix material is present in an amount which enablesprocessing of the material by at least one of the fabrication processesdescribed below. For example, the matrix material can be present in anamount of at least about 25%, more preferably from about 50% to about99%, based on the weight of the reinforced product.

The reinforced product can also be formed from an inorganic filler. Theamount and type of inorganic filler can depend on the desiredcharacteristics and properties of the reinforced product. For example,the inorganic filler can be present in an amount from 0% to about 50%,more preferably from about 15% to about 40%, based on the weight of thereinforced product.

The reinforced product includes a plurality of fibers for providingstructural reinforcement. While not wishing to be bound by anyparticular theory, it is believed that fibers which are excessivelyshort do not adequately contribute to the structural reinforcement ofthe product. Accordingly, the present fibers have dimensions whichenable them to provide structural reinforcement to the matrix material.For example, the fibers present in the reinforced product can have anaverage length of about 250 mm or less, more preferably about 50 mm orless, and most preferably from about 15 mm to about 38 mm. The fibersare preferably discontinuous as a result of the use thereof in one ofthe processes described below.

The fibers can be of a material that is effective to provide structuralreinforcement, and the specific material used can depend on thefabrication method employed, the specific application of the product,and/or the desired characteristics and properties of the product. Forexample, the plurality of fibers can comprise glass fibers, naturalfibers, polymer fibers such as polyester fibers, or a mixture thereof.In a preferred embodiment, the reinforced product includes glass fibers.

The fibers are present in an amount that is effective to providestructural reinforcement. For example, the fibers can be present in anamount of from about 1% to about 49%, preferably from about 1% to about15%, based on the weight of the reinforced product.

The shape of the fibers is not particularly limited, and the fibers canbe substantially regularly or irregularly shaped. In an exemplaryembodiment, fiber waste material can be used such as, for example,“basement fibers” which can be collected from below the floor level of aforming room in a fiber production facility. In embodiments wherediscontinuous fibers are initially used as the starting material, theaverage length of the discontinuous fibers in the reinforced product ispreferably at least about 70% to about 80% of the average initial lengthof such fibers. In embodiments where continuous fibers are initiallyused as the starting material, such continuous fibers are subjected toan increased degree of breakage in comparison with the use ofdiscontinuous fibers.

The discontinuous fibers can be distributed in the matrix material inany suitable manner for providing structural reinforcement, for example,in a substantially homogenous distribution. The distribution of thefibers in the matrix material can depend on the specific fabricationprocess employed, and various parameters of the processes can beadjusted to achieve varying degrees of distribution of the fibers.

In a first exemplary process for forming the reinforced product, anextrusion composition is provided which includes the matrix material. Aplurality of fibers is combined with the matrix material prior to orduring the extrusion step. The plurality of fiber can be combined withthe matrix material in any suitable manner. The material provided to theextruder can contain all of the components of the extrusion composition,or an initial material can be provided to the extruder and additionalcomponents can be added during the extrusion process. In an exemplaryembodiment, discrete components of the matrix can be introduced into anextruder which forms a suitable compound for combination with thefibers, and the fibers can then be combined therewith during extrusion.

The portion of the extrusion process in which the fibers are introducedand/or are present is preferably conducted under relatively low-shearconditions, for example, so as to reduce or avoid breakage of thefibers. The extrusion step is preferably conducted under conditionswhich enable “wet out” of the extruded material, i.e., the fibers andany other solid materials present in extrusion composition aresufficiently coated and dispersed in the extruded material.

Any extrusion apparatus capable of extruding the extrusion compositioncan be used. While not wishing to be bound to any particular theory, itis believed that maintaining a relatively long fiber length in theextruded material can increase the structural reinforcing effect of suchfibers. The dimensions of the extrusion apparatus preferably enable theextrusion composition to be extruded under low-shear conditions, so asto reduce the degree of breakage of the fibers as described above. Forexample, the extrusion apparatus can be a single-screw or twin-screwapparatus. In an exemplary embodiment, the extrusion apparatus can havea diameter of at least about 50 mm, and the length-to-diameter (L to D)ratio can be at least about 40, more preferably from about 40 to about50. An exemplary extrusion apparatus that can be used is available fromLeistritz located in Nuerenberg, Germany.

In a second exemplary process for forming the reinforced product, afirst layer comprising a first matrix material is formed. The firstmatrix material can be selected from the matrix materials describedabove. Preferably, the process can be conducted as a continuous processby, for example, providing the first layer on a conveyor belt. Anysuitable process for forming a layer from the matrix material can beused such as, for example, an extrusion process. The dimensions of thefirst layer are not particularly limited, and can depend on, forexample, the specific application of the reinforced product.

A plurality of fibers can then be provided on the first layer. Theplurality of fibers can be provided as discontinuous fibers that are notbound together. For example, the discontinuous fibers can besubstantially free of a binder that is typically used in the formationof fiber glass mats. Any suitable means for providing the fibers to thefirst layer can be used such as, for example, a fiber feeder apparatusavailable from Brabender Technologie Inc., located in Ontario, Canada.For example, the fiber feeder apparatus can be positioned above thefirst layer and substantially continuously deposit the fibers onto thefirst layer as such layer is conveyed under the fiber feeder apparatus.

A second layer comprising a second matrix material can be formed abovethe plurality of fibers. The second matrix material can be selected fromthe matrix materials described above, and can be the same as ordifferent from the first matrix material of the first layer. The secondlayer can be formed by any suitable process such as, for example, anextrusion process. Optionally, an additional step of providing aplurality of fibers and/or an additional step of forming a layer ofmatrix material can be conducted.

The plurality of fibers can then be introduced into the first matrixmaterial and/or the second matrix material. For example, the fibers canbe introduced to the matrix material by applying force to the firstlayer and/or the second layer. Any suitable means for applying force toeither or both of the first and second layers can be used. For example,the layers can be passed between an upper roller positioned above thelayers and a lower roller positioned below the layers, wherein thedistance between the rollers is less than overall thickness of thelayers.

While the reinforced product is produced by forming layers in separatesteps, the first and second layers can substantially blend into eachother in the final reinforced product. That is, the reinforced productcan contain either distinct and/or indistinct layers of material.

Also provided is a process for forming a plurality of precursorparticles suitable for use in a process for forming a reinforcedproduct. That is, the precursor particles can be employed in a processfor forming a reinforced product. The process for forming the precursorparticles includes providing at least one continuous fiber, andpreferably a plurality of continuous fibers. The at least one continuousfiber can be formed using any suitable means including, for example, byextrusion. The plurality of fibers can comprise glass fibers, hempfibers, wood fibers, polymer fibers such as polyester fibers or amixture thereof. In a preferred embodiment, the particles are at leastformed from glass fibers.

The at least one continuous fiber is at least partially coated with amatrix material using any suitable means, and preferably the outersurface of the at least one continuous fiber is substantially entirelycoated with the matrix material. The matrix material can be at leastpartially melted and applied to the fiber using a continuous melter, anextruder and/or a melt pump. The matrix material can be cooled and theresulting coated fiber can be provided as a final product or dividedinto smaller segments to form precursor particles for forming areinforced product. The coated fiber can be divided using any suitabledevice such as a conventional fiber chopping apparatus. The segments canhave any suitable length. For example, the segments can be divided suchthat the precursor particles have an average particle size of from about12 mm to about 25 mm. The shape of the precursor particles is notparticularly limited, and such particles can have cylindrical, sphericalor asymmetrical shapes.

A process for forming a reinforced product using the above-describedprecursor particles is also provided. The precursor particles can beheated under conditions effective to at least partially melt the matrixmaterial, thereby producing a heated material. The heated material canthen be introduced to a surface on which the reinforced product isformed. Any suitable means for applying the heated material can be usedsuch as, for example, a spraying process or coating process, andpreferably a spraying process. Applying the heated material by sprayingor coating can facilitate installation in irregularly shaped areasand/or areas in which installation would otherwise be difficult orinconvenient. In addition, transporting and/or storing the precursorparticles can be a more convenient alternative in comparison withtransporting/storing conventional products in finished form.

The reinforced product can include at least one additional layerdepending on the particular application of the product. For example, thereinforced product can include a clean-bond layer, a cover material, adecorative sheet, an insulation layer and/or a foam layer.

The dimensions and physical characteristics of the reinforced productcan depend on the specific intended application of the product. Forexample, the reinforced product can be provided in the form of anelongated sheet. Preferably, the elongated sheet can be rolled tofacilitate storage and transport of the material. The dimensions of theelongated sheet are not particularly limited and can depend on thespecific application of the sheet.

The reinforced product can be used in various applications such as, forexample, roofing applications for residential and/or commercialbuildings. In an exemplary embodiment, the reinforced product can beused in combination with conventional reinforcement materials such asmats formed from fiberglass and/or polyester.

While a detailed description of specific exemplary embodiments has beenprovided, it will be apparent to one of ordinary skill in the art thatvarious changes and modification can be made, and equivalents employedwithout departing from the scope of the claims.

1. A process for forming a reinforced product suitable for use as a roofing material, comprising: (a) providing a composition comprising a matrix material; and (b) extruding the composition with an extruder to form a reinforced product, wherein a plurality of fibers is combined with the matrix material prior to or during the extrusion step.
 2. The process for forming a reinforced product according to claim 1, wherein the plurality of fibers comprises glass fibers, natural fibers, polymer fibers or a mixture thereof.
 3. The process for forming a reinforced product according to claim 1, wherein the matrix material comprises bitumen, polymer-modified bitumen, a resin, a rubber, a plastic or a mixture thereof.
 4. The process for forming a reinforced product according to claim 1, wherein the average length of the plurality of fibers present in the reinforced product is about 50 mm or less.
 5. The process for forming a reinforced product according to claim 1, wherein the composition comprises the matrix material in an amount of from about 50% to about 99%, based on the weight of the composition.
 6. The process for forming a reinforced product according to claim 1, wherein the composition comprises the plurality of fibers in an amount of from about 1% to about 49%, based on the weight of the composition.
 7. The process for forming a reinforced product according to claim 1, wherein the composition further comprises an inorganic filler in an amount from about 15% to about 50%, based on the weight of the composition.
 8. The process for forming a reinforced product according to claim 1, wherein the extruder has a diameter of at least about 50 mm, and a length-to-diameter ratio of at least about
 40. 9. A reinforced product suitable for use as a roofing material formed by the process of claim
 1. 10. A process for forming a reinforced product suitable for use as a roofing material, comprising: (a) forming a first layer comprising a first matrix material; (b) providing a plurality of fibers on the first layer; (c) forming a second layer comprising a second matrix material, above the plurality of fibers; and (d) combining the plurality of fibers with the first matrix material and/or the second matrix material, to form a reinforced product.
 11. The process for forming a reinforced product according to claim 10, wherein the step (d) comprises applying force to the first layer and/or the second layer.
 12. The process for forming a reinforced product according to claim 10, wherein at least one of the first layer and the second layer is formed by an extrusion process.
 13. The process for forming a reinforced product according to claim 10, wherein the plurality of fibers comprises glass fibers, natural fibers, polymer fibers or a mixture thereof.
 14. The process for forming a reinforced product according to claim 10, wherein the matrix material comprises bitumen, polymer-modified bitumen, a resin, a rubber, a plastic or a mixture thereof.
 15. The process for forming a reinforced product according to claim 10, wherein the average length of the plurality of fibers present in the reinforced product is about 50 mm or less.
 16. The process for forming a reinforced product according to claim 10, wherein the total amount of the first and second matrix materials is from about 50% to about 99%, based on the weight of the reinforced product.
 17. The process for forming a reinforced product according to claim 10, wherein the plurality of fibers is present in an amount of from about 1% to about 49%, based on the weight of the reinforced product.
 18. The process for forming a reinforced product according to claim 10, wherein an inorganic filler is present in an amount from about 1% to about 40%, based on the weight of the reinforced product.
 19. A reinforced product suitable for use as a roofing material formed by the process of claim
 10. 20. A process for forming a plurality of precursor particles suitable for use in a process for forming a reinforced product, comprising: (a) providing at least one continuous fiber; (b) at least partially coating the at least one continuous fiber with a matrix material; and (c) dividing the at least partially coated continuous fiber to form a plurality of precursor particles.
 21. A process for forming a reinforced product from a plurality of precursor particles, wherein each precursor particle comprises a fiber at least partially coated with a matrix material, the process comprising: (a) heating the plurality of precursor particles under conditions effective to at least partially melt the matrix material, thereby producing a heated material; and (b) introducing the heated material to a surface on which the reinforced product is formed.
 22. The process for forming a reinforced product according to claim 21, wherein the step (b) comprises spraying or coating the heated material on the surface.
 23. A reinforced product suitable for use as a roofing material formed by the process of claim
 21. 